Classification & Evolution Flashcards
What is taxonomy?
Practice of biological classification
What is hierarchical classification? What are the groups?
used to organise and group similar organisms together
DOMAIN
KINGDOM
PHYLUM
CLASS
ORDER
FAMILY
GENUS
SPECIES
Why are binomial names important? What do they consist of/who developed this naming system?
They allow for the species to be universally identified
Carl Linnaeus created binomial system
Consist of genus and species name
What are the 3 domains?
Bacteria (prokaryotes) - no nucleus /vary in size
Archaea (prokaryotes)- smaller size range
Eukarya (eukaryotes) - nuclei and membrane bound organelle
- vary in size
- 80S ribosomes/linear DNA
Difference between archaea and bacteria ?
Archaea have :
Unique membrane lipids
Ribosomal DNA - *base sequence of rRNA more similar to that in eukarya than bacteria
- primary structure of ribosome proteins in archaea more similar to proteins in eukarya
Composition of cell wall - cell wall dont contain peptidoglycan
Have histones
What are the 5 kingdoms?
Prokaryota - no nucleus/mitochondria
- unicellular
Domain : eukarya
Protoctista - mostly single celled but can be multicellular , eukaryotic cells (autotrophic/heterotrophic)
Fungi- chitin cell wall/ single celled/multicellular / saprotrophic (absorb substance from dead organisms)
Plantae- multicellular, cellulose cell wall , autotrophic (produce own food)
Animalia - multicellular , no cell wall , heterotrophic (consume plants/animals)
What is homology?
Grouping organisms based on features they shared
What is phylogeny?
Evolutionary history of organisms
What are phylogenetic trees?
Diagrams to show evolutionary relationship between different taxa
What sequence data is used to investigate evolutionary relationships?
DNA - how its stored /sequence of bases
MRNA
Amino acids - sequcne of amino acids compared to
- the more similar the amino acid sequence in cytochrome C in 2 different species, the more closely related they are
For all sequence data , the more similar the sequences, the more closely related the species are. - Species that have been separated for longer have had more time for mutations in DNA,mRNA and amino acid sequences - so less closely related
What evidence does classification system use to identify how closely related organisms are?
Observable features - can’t be only thing used as scientist disagree on importance of different features
Molecular evidence- mRNA/DNA/proteins
Embryological evidence - similarities are early stage of development
Anatomical evidence - similarity in structure/fucntion of body parts
Behavioral evidence - similarity in behavior/social organisation
What is evolution?
Change in adaptive features of a population over time as a result of natural selection
Darwin’s key observations that helped develop theory of evolution?
- organisms produce more offspring than could survive
- populations of organisms fluctuate - not much
- variation in characteristics in populations of same species
- offspring inherit characteristics from parents
Evidence for the Theory of Evolution?
Fossil evidence - can tell that environments have changed significantly
- can be dated so put organisms in order from oldest to youngest and see how they changed
- show similarities between extinct species/ancestral species and species today
Molecular evidence - DNA can provide evidence for evolutionary relationships between species/how genetic code of species has changed
- more similar sequence is , more closely related it is
Those will more similar sequences will have been separated RECENTLY , than those with very different sequences
2 types of variation?
Genetic variation: variation in genotypes between species (interspecific) /within a species (intraspecific)
Phenotypic variation: variation in phenotypes between species or within species